The present invention relates generally to knitted articles and methods for knitting same, and more particularly, to knitted athletic socks and similar hosiery articles and circular knitting methods utilizing circular hosiery knitting machines.
The recent increased awareness and concern for personal health and fitness has generated a considerable amount of activity in the apparel industry directed to satisfying the correspondingly increasing market for athletic apparel. With the ever increasing numbers of persons actively participating in jogging, running, aerobics, tennis and similar relatively strenuous physical activities which impose considerble forces and stresses on the feet, much attention is presently given to optimizing the protective and comfort features of athletic socks and other athletic footwear particularly designed for such activities.
Substantially all conventional athletic socks are now produced by a circular knitting method or circular hosiery knitting machines and it has long been the practice to knit such socks with a so-called "cushion sole" of a terry pile loop construction. In its simplest form, an athletic sock having this cushion sole feature has a relatively bulky, high denier, absorbent body yarn and a second, normally low denier, ground yarn knit throughout the sock in plated relationship, with the body yarn formed in terry pile loops in at least the lower sole area of the foot portion of the sock and often throughout the entirety thereof. This so-called "single terry" knitted fabric construction provides the sock with an increased thickness and a resulant degree of cushioning for the wearer's foot, as well as enabling the wicking of perspiration away from the foot. However, the terry pile loops in such a single terry fabric have a tendency to substantially flatten under the stresses of strenuous physical exercise, thereby minimizing the intended cushioning and moisture wicking effects.
As a possible solution to these and other inadequacies of such single terry cushion sole athletic socks, it has been proposed to incorporate a second terry body yarn in the "cushion" areas of such socks to provide a second set of terry pile loops for increased cushioning, foot support and moisture absorbing capabilities. Examples of athletic socks of this type are disclosed in U.S. Pat. Nos. 3,793,851; 4,149,249; 4,277,959; and 4,373,361. While this so-called "double terry" knitted fabric construction essentially doubles the amount of yarn and the number of terry loops in the cushion areas of these socks to provide some increased ability for cushioning and moisture absorption, the terry pile loops of each terry yarn are essentially identical in size and shape and are located in identical walewise alignment with one another just as with a single set of terry loops in a single terry fabric. Accordingly, the terry loops in such a double terry fabric have been found to suffer a similar tendency to flatten during strenuous physical activity, thereby minimizing the additional cushioning and wicking effect of the second terry yarn.
In contrast, the present invention provides a novel knitted construction and method for knitting a cushion area having two sets of terry loops of differing heights and staggered orientations with respect to one another whereby the terry loops provide better elongation and upstanding support for one another with resultantly improved cushioning and moisture wicking abilities.
Another disadvantage of the above-discussed conventional double terry fabric is that it must be knitted on a circular knitting machine utilizing a so-called "chopping" yarn feeding finger for the second terry body yarn. The chopping finger is operable to pivot into and out of a yarn feeding position during each revolution of the knitting machine to selectively place the second terry body yarn on only the knitting needles in a section, e.g. one-half, of the needle cylinder and to prevent the receipt of the second yarn by the other cylinder needles. At the rotational speeds at which circular hosiery knitting machines typically are operated, it is difficult to insure the exact synchronization of the chopping finger to the rotation of the needle cylinder to insure the starting and stopping of the second terry body yarn on the same needles during each cylinder revolution. It is therefore not unusual to suffer missed stitches while utilizing a chopping feed finger in this manner and typically this type of knitting machine must be operated at a slower than desirable speed to minimize such defects. Furthermore, the chopping feed finger of such machines is incapable of selectively feeding the second terry body yarn to only selected spaced needles since this would require the repetitive chopping movement of the finger into and out of feeding position for substantially each selected needle during each cylinder revolution and, of course, it is not possible to so precisely control the operation of the chopping finger synchronously with the cylinder.
In contrast, the knitting method of the present invention enables the feed finger for the second terry yarn to be positioned and left stationary at its desired yarn feeding position throughout the entire knitting operation and further permits the selective feeding of the second terry yarn to any desired combination of cylinder needles within the same cylinder revolution.
Another common complaint concerning conventional athletic socks is the failure of the leg portion to provide sufficient elasticity to comfortably accommodate large calf sizes while also preventing slippage of the leg portion of the socks down the wearer's legs. To some extent, these two considerations are divergent in that, to accommodate large size calves, the leg portion of a sock must have a substantial degree of stretchability, which in certain cases may compromise the ability of the leg portion of the sock to hold to the wearer's leg against slipping, whereas a lesser degree of stretchability for the leg portion of the sock better insures against slippage but compromises the ability to accommodate large calf sizes.
Typically, athletic socks are provided with a leg portion or at least an elastic cuff portion of a so-called "mock rib" construction having a stretchable elastic yarn inlaid in periodically spaced wales of the leg or cuff portion, thereby providing the leg or cuff portion with a significant degree of coursewise stretchability. Such mock rib constructions are designated according to the number of wales in which the elastic yarn is inlaid and the number of wales over which the elastic yarn is floated in each repeat of the mock-rib construction. For example, a mock rib construction having the elastic yarn inlaid in every other wale is designated as a one-by-one (1.times.1) mock rib, a mock rib construction having the elastic yarn inlaid in every third wale is designated as a one-by-two (1.times.2) mock rib, and so forth. Conventionally, the same mock rib construction is utilized about the entire circumference of the leg or cuff portion of the sock. Accordingly, the leg or cuff portion has the same degree of stretchability about its entire circumference which fails to provide for the necessity that the leg or cuff portion will stretch considerably more in the rear calf area to accommodate the wearer's calf muscles than in the front shin area.
In contrast, the athletic sock of the present invention provides an elastic cuff having distinct and differently stretchable calf and shin areas to enable adequate stretching to conform to and accommodate the wearer's calf muscles while also providing sufficient snugness and support on the wearer's leg to prevent slippage of the leg portion of the sock.